ObjectiveTo explore the necessity of repairing the deep layer of deltoid ligament in the treatment of mixed medial injury associated with ankle fractures.MethodsBetween January 2016 and December 2018, 12 patients with mixed medial injury associated with ankle fractures were treated with the fixation of the lateral malleolus by bone plates, the fixation of the anterior colliculus of medial malleolus by cannulated screws, and the repair of the deltoid ligament by suture anchors. There were 8 males and 4 females, with an average age of 42 years (range, 18-56 years). According to the Lauge-Hansen classification criteria, there were 11 cases of supination-external rotation type and 1 case of pronation-external rotation type. According to the Weber classification criteria, all cases were type B. The time from injury to operation was 3-6 days, with an average of 4.7 days. In each patient, X-ray films of anteroposterior and lateral views and mortise view of ankle were taken postoperatively. The motion range of ankle joints was observed. The function of the ankle and the outcome of the treatment were evaluated according to the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system, Olerud-Molander scoring system, and the visual analogue scale (VAS) score.ResultsAll cases were followed up 12-42 months (mean, 28 months). The 12 patients returned to their pre-injury jobs. Five patients with sports injury completely recovered to their pre-injury motor function. No patient experienced persistent medial ankle pain or ankle instability. At last follow-up, the ankle range of motion in dorsiflexion was 9°-25° (mean, 17.96°), which was 0°-11° (mean, 4.02°) less than that in normal side; the range of motion in plantar flexion was 38°-50° (mean, 43.90°), which was 0°-7° (mean, 2.53°) less than that in normal side. The AOFAS score was 88-100 (mean, 96.7); the Olerud-Molander score was 90-100 (mean, 96.5); the VAS score was 0-3 (mean, 1.1).ConclusionIt is necessary to repair the deep layer of deltoid ligament in the mixed medial injuries associated with ankle fracture, which include anterior colliculus fracture and deep deltoid ligament injury. A better outcome can be achieved by employing the suture anchor repair method.